Device for stabilizing an electric consumer voltage with a leakage resistance transformer



May 9, 1967 A. H. WALZ T AL 3,319,205

DEVICE FOR STABILIZING AN ELECTRIC CONSUMER VOLTAGE WITH 7 A LEAKAGE RESISTANCE TRANSFORMER.

Filed May 28, 1965 v 2 Sheets-Sheet 1 Fig.1

-[NVENTOR mmeo H- \nl/JLZ S ROBERT dsTRE/(HER Mil/WW 3,319,205 SUMER VOLTAGE WITH FORMER May 9, 1967 W ET AL DEVICE FOR STABILIZING 'AN ELECTRIC CON A LEAKAGE RESISTANCE TRANS 2 Sheets-Sheet 2 Filed May 28, 1965 Fig.3

United States Patent DEVICE FOR STABILIZING AN ELECTRIC CON- SUMER VOLTAGE WITH A LEAKAGE RESIST- ANCE TRANSFURMER Alfred H. Walz, Emmendingen, Baden, and Robert 0streicher, Teningen, Baden, Germany, assignors to Frako Kondensatorenund Apparatebau G.rn.b.H., Teningen, Baden, Germany, a corporation of Germany Filed May 28, 1965, Ser. No. 459,798

Claims priority, application Germany, June 5, 1964,

3 Claims. (ci. 336-165) Application Ser. No. 225,282, :filed Sept. 21, 1962, relates to a device for stabilizing an electric load voltage with a leakage resistance transformer, with a secondary winding connected with a condenser to form a resonant circuit. A leakage or stray flux path of increased magnetic resistance is arranged between the primary and secondary windings in such a manner that a portion of the magnetic flux can thread with one of the windings, excluding the other. The transformer core is built up from sheet metal laminations with preferred magnetic direction, and the leakage or stray flux path is formed by a core piece, separate from the main core, likewise threaded by the magnetic flux in preferred magnetic direction, and which, while embracing at least one transformer winding, is placed laterally on the main core. To obtain the increased magnetic leakage resistance, at least one air gap is provided, in known manner, between the separate core piece and the main core.

The object of the invention is to further develop the subject matter of the mentioned application. This is achieved in that the core of the transformer comprises a straight or rectilinear core piece carrying the primary winding, on one side of which a U-shaped core piece carrying the secondary winding and, on the opposite side a likewise U-shaped core piece forming the stray flux path, are placed, in the latter case in a manner forming air gaps. The secondary winding is preferably composed of two sections which are arranged one on each of the two arms of the U-shaped core piece. By the construction of the core pieces and the arrangement of the windings according to the invention, a more advantageous initial characteristic curve can be attained.

The invention is hereinafter described as applied to several embodiments illustrated by way of example in the accompanying drawings, in which:

FIG. 1 is a sectioned perspective view of a leakage resistance transformer with a single secondary winding,

FIG. 2 is a sectioned perspective view of a leakage resistance transformer 'with separate secondary winding sections, and

FIG. 3 is a sectioned perspective view of a leakage re sistance transformer in which the core piece carrying the secondary winding is composed of two parts.

In FIG. 1 the main magnetic flux path consists of a U-shaped core piece composed of laminations with preferred magnetic direction and a straight or rectilinear core piece 11, which is also composed of laminations with preferred magnetic direction. The U-shaped core piece 10 is placed with the end faces of its arms 10a and 10b laterally abutting the straight core piece 11. The secondary winding 13 is slipped on the arm 10a of the core piece 10, Whereas the primary winding 14 is arranged on the straight core piece 11.

The primary winding 14 is overlapped by the U-shaped core piece 12 forming the stray flux path, which is also placed with its arms 12a and 12b extending laterally of the straight core piece 11 and having therein spaces spaced therefrom to form air gaps 16.

In FIG. 2 the U-shaped core piece carrying the secondary winding is designated by 20. 21 is the straight rectilinear core piece and 22 the U-shaped core piece forming the stray flux path and which is placed on the straight core piece 21 with its end faces spaced therefrom to form air gaps 26. The end faces 25 of the arms 20a and 20b of the U-shaped. core piece 20 are placed against the straight core piece 21 at 25 practically without forming air gaps.

The straight core piece 21 carries the primary winding 24. The secondary winding is divided into two sections 23a and 2317, the section 23a being placed on the arm 20a and the section 23b on the arm 20b.

In FIG. 3 the core piece carrying the secondary winding 33 consists of two L-shaped parts 30a and 30b fitted together at 37 practically without forming an air gap. The U-shaped core piece formed in this manner by the two L-shaped parts 30a and 3% has its end faces placed against the straight core piece 31 practically without forming air gaps. The straight core piece 31 carries the primary winding.

The U-shaped core piece 32 forming the stray fiux path is placed with its end faces spaced from the straight core piece 31, forming air gaps 36.

All core pieces are composed of laminations with preferred magnetic direction and produced in substantially the same way as cut band cores.

What we claim is:

1. A stray field transformer for stabilizing a load circuit and for use in a resonant circuit including an inductance and a condenser, said transformer comprising, in combination, a relatively elongated rectilinear laminated main core whose laminations have the same magnetic flow preferential direction; a first Ushaped laminated magnetic core, whose laminations have the same magnetic flow preferential direction, having the end faces of its legs firmly abutting a lateral face of said ma-in core at opposite ends of the latter to form therewith a substantially uninterrupted magnetic circuit having a relatively low magnetic resistance; a second U-shaped laminated magnetic core, whose laminations have the same magnetic flow preferential direction, having the end faces of its legs adjacent but spaced from the opposite lateral surface of said main core, at opposite ends of the latter, to form a pair of air gaps with said main core and forming, with said main core, a stray flux path having a relatively higher magnetic resistance; a primary winding wound on said main core and partially embraced by said first U- sh-aped core; and a secondary winding wound on at least one leg of said first U-shaped core, and adapted to constitute the inductance of the resonant circuit; said second U-shaped core partially embracing said primary winding, whereby said primary winding and said secondary winding are traversed by magnetic fluxes of different values.

2. A stray field transformer, as claimed in claim 1, in which said secondary winding comprises two secondary winding sections, one section being arranged on each of the two arms of said first U-shaped core.

3. A stray field transformer, as claimed in claim 1, in which said first U-shaped laminated magnetic core comprises two mating L-shaped laminated magnetic cores having end faces of corresponding legs abutted to form said first U-shaped laminated magnetic core.

References Cited by the Examiner UNITED STATES PATENTS 1,992,822 2/1935 Granfield 336-212 X 2,324,634 7/1943 McCreary 336- X 2,558,110 6/1951 Stein 3362l4 X 3,238,484 3/1966 Dacey 336-205 X LEWIS H. MYERS, Primary Examiner. T. I. KOZMA, Assistant Examiner. 

1. A STRAY FIELD TRANSFORMER FOR STABILIZING A LOAD CIRCUIT AND FOR USE IN A RESONANT CIRCUIT INCLUDING AN INDUCTANCE AND A CONDENSER, SAID TRANSFORMER COMPRISING, IN COMBINATION, A RELATIVELY ELONGATED RECTILINEAR LAMINATED MAIN CORE WHOSE LAMINATIONS HAVE THE SAME MAGNETIC FLOW PREFERENTIAL DIRECTION; A FIRST U-SHAPED LAMINATED MAGNETIC CORE, WHOSE LAMINATIONS HAVE THE SAME MAGNETIC FLOW PREFERENTIAL DIRECTION, HAVING THE END FACES OF ITS LEGS FIRMLY ABUTTING A LATERAL FACE OF SAID MAIN CORE AT OPPOSITE ENDS OF THE LATTER TO FORM THEREWITH A SUBSTANTIALLY UNINTERRUPTED MAGNETIC CIRCUIT HAVING A RELATIVELY LOW MAGNETIC RESISTANCE; A SECOND U-SHAPED LAMINATED MAGNETIC CORE, WHOSE LAMINATIONS HAVE THE SAME MAGNETIC FLOW PREFERENTIAL DIRECTION, HAVING THE END FACES OF ITS LEGS ADJACENT BUT SPACED FROM THE OPPOSITE LATERAL SURFACE OF SAID MAIN CORE, AT OPPOSITE ENDS OF THE LATTER, TO FORM A PAIR OF AIR GAPS WITH SAID MAIN CORE AND FORMING, WITH SAID MAIN CORE, A STRAY FLUX PATH HAVING A RELATIVELY HIGHER MAGNETIC RESISTANCE; A PRIMARY WINDING WOUND ON SAID MAIN CORE AND PARTIALLY EMBRACED BY SAID FIRST USHAPED CORE; AND A SECONDARY WINDING WOUND ON AT LEAST ONE LEG OF SAID FIRST U-SHAPED CORE, AND ADAPTED TO CONSTITUTE THE INDUCTANCE OF THE RESONANT CIRCUIT; SAID SECOND U-SHAPED CORE PARTIALLY EMBRACING SAID PRIMARY WINDING, WHEREBY SAID PRIMARY WINDING AND SAID SECONDARY WINDING ARE TRAVERSED BY MAGNETIC FLUXES OF DIFFERENT VALUES. 